CASE STUDIES

FIRES involving LITHIUM ION BATTERIES
Due to the excellent features of lithium-ion battery – energy density, high power capacity, stable voltage, long life cycle and low self-discharge, this technology has been widely applied in various applications, such as portable electronics, electric vehicles and energy storage. Li-Ion battery cells contain high energy and combustible materials (i.e., electrode, separator, electrolyte and organic solvents), if it is abused to the point of internal failure the cell can initiate a fire. The potential threats formed by lithium-ion batteries demand an specific fire safety concept.

Fire is due to failure in the Battery cell – causes include:
  ●   Mechanical damage to the battery cells – due to penetration of cell or excessive vibration.
  ●   Exposure of the battery cells to heat.
  ●   Overcharging battery – charging batteries below freezing can also be an issue.
  ●   Uncontrolled or a (too) fast discharge of stored chemical energy, through a defect or incorrect treatment.
  ●   Production issues related to the cell such as polluted or poor quiality components.

Thermal Runaway in batteries can be caused when the cell is in failure. Lithium ion battery cells are a closed system. When the cell is in failure an exothermic reaction occurs – the cell heats up. With the rising up of the battery temperature, more chemical reactions occur, and more heat generation. Once the heat generation is greater than the heat loss, the battery system can arrive at ‘temperature of no return’, then thermal runaway. The heat generation is decided by the materials, and the heat loss decided by the cell housing and location of cells. This will then affect ajoining cells.

Characteristics the Fire – A Li-Ion fire is difficult to fight due to the chemical reaction continuously creating oxygen. The organic electrolytes in many lithium ion batteries are highly flammable when heated. The fire can result in temperatures in excess of 1,200°C, and also release hot and corrosive solid compounds. Quantities of toxic gases can be generated during the thermal runaway process such as Hydrogen fluoride (HF), carbon monoxide (CO), nitric oxide (NO), sulfur dioxide (SO2), hydrogen chloride (HCl) and hydrogen (H2).

Testing of fire extinguishing scenarios involving Lithium-ion batteries was completed using number of real fire scenarios. During these tests the capability and effectiveness of the FirePro Condensed Aerosol Fire Extinguishing Technology to suppress such fires, was assessed. The results confirmed that FirePro offers an extremely effective and efficient way to extinguish a lithium-ion fire.